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authorTom Gundersen <teg@jklm.no>2014-02-13 20:56:16 +0100
committerTom Gundersen <teg@jklm.no>2014-02-15 12:14:45 +0100
commite5002702716b047c3d5515aaeecc5b829db02aa4 (patch)
treeabd448e721d74bdf09c0adf1518b0eb62b22c981
parentee3a6a51e5b098aa0c9641ed71d275c459ad2f5a (diff)
sd-dhcp-client: explicitly handle raw and udp messages
Split the recevie_message callback into _raw and _udp parts and a generic DHCPMessage handler. Also always verify the xid/MAC, rather than only for udp messages.
-rw-r--r--src/libsystemd-dhcp/sd-dhcp-client.c196
1 files changed, 110 insertions, 86 deletions
diff --git a/src/libsystemd-dhcp/sd-dhcp-client.c b/src/libsystemd-dhcp/sd-dhcp-client.c
index 3b4db1d96f..39c2eebffc 100644
--- a/src/libsystemd-dhcp/sd-dhcp-client.c
+++ b/src/libsystemd-dhcp/sd-dhcp-client.c
@@ -70,8 +70,10 @@ static const uint8_t default_req_opts[] = {
DHCP_OPTION_NTP_SERVER,
};
-static int client_receive_message(sd_event_source *s, int fd,
- uint32_t revents, void *userdata);
+static int client_receive_message_raw(sd_event_source *s, int fd,
+ uint32_t revents, void *userdata);
+static int client_receive_message_udp(sd_event_source *s, int fd,
+ uint32_t revents, void *userdata);
int sd_dhcp_client_set_callback(sd_dhcp_client *client, sd_dhcp_client_cb_t cb,
void *userdata) {
@@ -357,7 +359,7 @@ static int client_timeout_resend(sd_event_source *s, uint64_t usec,
switch (client->state) {
case DHCP_STATE_RENEWING:
- time_left = (client->lease->t2 - client->lease->t1)/2;
+ time_left = (client->lease->t2 - client->lease->t1) / 2;
if (time_left < 60)
time_left = 60;
@@ -367,7 +369,7 @@ static int client_timeout_resend(sd_event_source *s, uint64_t usec,
case DHCP_STATE_REBINDING:
- time_left = (client->lease->lifetime - client->lease->t2)/2;
+ time_left = (client->lease->lifetime - client->lease->t2) / 2;
if (time_left < 60)
time_left = 60;
@@ -398,7 +400,8 @@ static int client_timeout_resend(sd_event_source *s, uint64_t usec,
if (r < 0)
goto error;
- r = sd_event_source_set_priority(client->timeout_resend, client->event_priority);
+ r = sd_event_source_set_priority(client->timeout_resend,
+ client->event_priority);
if (r < 0)
goto error;
@@ -455,19 +458,21 @@ error:
return 0;
}
-static int client_initialize_events(sd_dhcp_client *client, usec_t usec) {
+static int client_initialize_events(sd_dhcp_client *client,
+ sd_event_io_handler_t io_callback,
+ usec_t usec) {
int r;
assert(client);
assert(client->event);
- r = sd_event_add_io(client->event, client->fd, EPOLLIN,
- client_receive_message, client,
- &client->receive_message);
+ r = sd_event_add_io(client->event, client->fd, EPOLLIN, io_callback,
+ client, &client->receive_message);
if (r < 0)
goto error;
- r = sd_event_source_set_priority(client->receive_message, client->event_priority);
+ r = sd_event_source_set_priority(client->receive_message,
+ client->event_priority);
if (r < 0)
goto error;
@@ -477,7 +482,8 @@ static int client_initialize_events(sd_dhcp_client *client, usec_t usec) {
if (r < 0)
goto error;
- r = sd_event_source_set_priority(client->timeout_resend, client->event_priority);
+ r = sd_event_source_set_priority(client->timeout_resend,
+ client->event_priority);
error:
if (r < 0)
@@ -518,10 +524,12 @@ static int client_timeout_t2(sd_event_source *s, uint64_t usec, void *userdata)
client->fd = r;
- return client_initialize_events(client, usec);
+ return client_initialize_events(client, client_receive_message_raw,
+ usec);
}
-static int client_timeout_t1(sd_event_source *s, uint64_t usec, void *userdata) {
+static int client_timeout_t1(sd_event_source *s, uint64_t usec,
+ void *userdata) {
sd_dhcp_client *client = userdata;
int r;
@@ -537,47 +545,23 @@ static int client_timeout_t1(sd_event_source *s, uint64_t usec, void *userdata)
client->fd = r;
- return client_initialize_events(client, usec);
+ return client_initialize_events(client, client_receive_message_udp, usec);
}
-static int client_verify_headers(sd_dhcp_client *client, DHCPPacket *message,
- size_t len) {
- int r;
-
- r = dhcp_packet_verify_headers(message, BOOTREPLY, len);
- if (r < 0)
- return r;
-
- if (be32toh(message->dhcp.xid) != client->xid)
- return -EINVAL;
-
- if (memcmp(&message->dhcp.chaddr[0], &client->mac_addr.ether_addr_octet,
- ETHER_ADDR_LEN))
- return -EINVAL;
-
- return 0;
-}
-
-static int client_receive_offer(sd_dhcp_client *client, DHCPPacket *offer,
- size_t len) {
+static int client_handle_offer(sd_dhcp_client *client, DHCPMessage *offer,
+ size_t len) {
_cleanup_dhcp_lease_unref_ sd_dhcp_lease *lease = NULL;
int r;
- r = client_verify_headers(client, offer, len);
- if (r < 0)
- return r;
-
r = dhcp_lease_new(&lease);
if (r < 0)
return r;
- len = len - DHCP_IP_UDP_SIZE;
- r = dhcp_option_parse(&offer->dhcp, len, dhcp_lease_parse_options,
- lease);
+ r = dhcp_option_parse(offer, len, dhcp_lease_parse_options, lease);
if (r != DHCP_OFFER)
return -ENOMSG;
- lease->address = offer->dhcp.yiaddr;
+ lease->address = offer->yiaddr;
if (lease->address == INADDR_ANY ||
lease->server_address == INADDR_ANY ||
@@ -591,38 +575,23 @@ static int client_receive_offer(sd_dhcp_client *client, DHCPPacket *offer,
return 0;
}
-static int client_receive_ack(sd_dhcp_client *client, const uint8_t *buf,
- size_t len) {
- DHCPPacket *ack;
- DHCPMessage *dhcp;
+static int client_handle_ack(sd_dhcp_client *client, DHCPMessage *ack,
+ size_t len) {
_cleanup_dhcp_lease_unref_ sd_dhcp_lease *lease = NULL;
int r;
- if (client->state == DHCP_STATE_RENEWING) {
- dhcp = (DHCPMessage *)buf;
- } else {
- ack = (DHCPPacket *)buf;
-
- r = client_verify_headers(client, ack, len);
- if (r < 0)
- return r;
-
- dhcp = &ack->dhcp;
- len -= DHCP_IP_UDP_SIZE;
- }
-
r = dhcp_lease_new(&lease);
if (r < 0)
return r;
- r = dhcp_option_parse(dhcp, len, dhcp_lease_parse_options, lease);
+ r = dhcp_option_parse(ack, len, dhcp_lease_parse_options, lease);
if (r == DHCP_NAK)
return DHCP_EVENT_NO_LEASE;
if (r != DHCP_ACK)
return -ENOMSG;
- lease->address = dhcp->yiaddr;
+ lease->address = ack->yiaddr;
if (lease->address == INADDR_ANY ||
lease->server_address == INADDR_ANY ||
@@ -681,7 +650,8 @@ static int client_set_lease_timeouts(sd_dhcp_client *client, uint64_t usec) {
if (r < 0)
return r;
- r = sd_event_source_set_priority(client->timeout_t1, client->event_priority);
+ r = sd_event_source_set_priority(client->timeout_t1,
+ client->event_priority);
if (r < 0)
return r;
@@ -706,7 +676,8 @@ static int client_set_lease_timeouts(sd_dhcp_client *client, uint64_t usec) {
if (r < 0)
return r;
- r = sd_event_source_set_priority(client->timeout_t2, client->event_priority);
+ r = sd_event_source_set_priority(client->timeout_t2,
+ client->event_priority);
if (r < 0)
return r;
@@ -722,40 +693,34 @@ static int client_set_lease_timeouts(sd_dhcp_client *client, uint64_t usec) {
if (r < 0)
return r;
- r = sd_event_source_set_priority(client->timeout_expire, client->event_priority);
+ r = sd_event_source_set_priority(client->timeout_expire,
+ client->event_priority);
if (r < 0)
return r;
return 0;
}
-static int client_receive_message(sd_event_source *s, int fd,
- uint32_t revents, void *userdata) {
- sd_dhcp_client *client = userdata;
- uint8_t buf[sizeof(DHCPPacket) + DHCP_CLIENT_MIN_OPTIONS_SIZE];
- int buflen = sizeof(buf);
- int len, r = 0, notify_event = 0;
- DHCPPacket *message;
- usec_t time_now;
+static int client_handle_message(sd_dhcp_client *client, DHCPMessage *message,
+ int len, usec_t time_now) {
+ int r = 0, notify_event = 0;
- assert(s);
assert(client);
assert(client->event);
+ assert(message);
- len = read(fd, &buf, buflen);
- if (len < 0)
- return 0;
+ if (be32toh(message->xid) != client->xid)
+ return -EINVAL;
- r = sd_event_get_now_monotonic(client->event, &time_now);
- if (r < 0)
- goto error;
+ if (memcmp(&message->chaddr[0], &client->mac_addr.ether_addr_octet,
+ ETHER_ADDR_LEN))
+ return -EINVAL;
switch (client->state) {
case DHCP_STATE_SELECTING:
- message = (DHCPPacket *)&buf;
-
- if (client_receive_offer(client, message, len) >= 0) {
+ r = client_handle_offer(client, message, len);
+ if (r >= 0) {
client->timeout_resend =
sd_event_source_unref(client->timeout_resend);
@@ -770,7 +735,8 @@ static int client_receive_message(sd_event_source *s, int fd,
if (r < 0)
goto error;
- r = sd_event_source_set_priority(client->timeout_resend, client->event_priority);
+ r = sd_event_source_set_priority(client->timeout_resend,
+ client->event_priority);
if (r < 0)
goto error;
}
@@ -781,7 +747,7 @@ static int client_receive_message(sd_event_source *s, int fd,
case DHCP_STATE_RENEWING:
case DHCP_STATE_REBINDING:
- r = client_receive_ack(client, buf, len);
+ r = client_handle_ack(client, message, len);
if (r == DHCP_EVENT_NO_LEASE)
goto error;
@@ -832,6 +798,62 @@ error:
return 0;
}
+static int client_receive_message_raw(sd_event_source *s, int fd,
+ uint32_t revents, void *userdata) {
+ sd_dhcp_client *client = userdata;
+ uint8_t buf[sizeof(DHCPMessage) + DHCP_CLIENT_MIN_OPTIONS_SIZE];
+ int buflen = sizeof(buf);
+ int len, r = 0;
+ usec_t time_now;
+
+ assert(s);
+ assert(client);
+ assert(client->event);
+
+ len = read(fd, &buf, buflen);
+ if (len < 0)
+ return 0;
+
+ r = sd_event_get_now_monotonic(client->event, &time_now);
+ if (r < 0)
+ return client_stop(client, r);
+
+ return client_handle_message(client, (DHCPMessage *) buf, len,
+ time_now);
+}
+
+static int client_receive_message_udp(sd_event_source *s, int fd,
+ uint32_t revents, void *userdata) {
+ sd_dhcp_client *client = userdata;
+ uint8_t buf[sizeof(DHCPPacket) + DHCP_CLIENT_MIN_OPTIONS_SIZE];
+ int buflen = sizeof(buf);
+ int len, r = 0;
+ DHCPPacket *packet;
+ usec_t time_now;
+
+ assert(s);
+ assert(client);
+ assert(client->event);
+
+ len = read(fd, &buf, buflen);
+ if (len < 0)
+ return 0;
+
+ packet = (DHCPPacket *) buf;
+
+ r = dhcp_packet_verify_headers(packet, BOOTREPLY, len);
+ if (r < 0)
+ return r;
+
+ len -= DHCP_IP_UDP_SIZE;
+
+ r = sd_event_get_now_monotonic(client->event, &time_now);
+ if (r < 0)
+ return client_stop(client, r);
+
+ return client_handle_message(client, &packet->dhcp, len, time_now);
+}
+
int sd_dhcp_client_start(sd_dhcp_client *client) {
int r;
@@ -854,14 +876,16 @@ int sd_dhcp_client_start(sd_dhcp_client *client) {
client->start_time = now(CLOCK_MONOTONIC);
client->secs = 0;
- return client_initialize_events(client, client->start_time);
+ return client_initialize_events(client, client_receive_message_udp,
+ client->start_time);
}
int sd_dhcp_client_stop(sd_dhcp_client *client) {
return client_stop(client, DHCP_EVENT_STOP);
}
-int sd_dhcp_client_attach_event(sd_dhcp_client *client, sd_event *event, int priority) {
+int sd_dhcp_client_attach_event(sd_dhcp_client *client, sd_event *event,
+ int priority) {
int r;
assert_return(client, -EINVAL);